This invention relates to a system for detecting wetness in clothing and more particularly to a system for detecting the presence of urine in clothing worn by a infant or patient.
There are a variety of devices for sounding an alarm when an infant urinates in a diaper being worn by the infant. The reason for providing such alarm may be two-fold: (1) to alert the person caring for the infant that the diaper is wet and needs to be changed; and/or (2) to produce a startling or unpleasant event for the infant when the infant wets, hopefully leading to toilet training of the infant.
Devices such as described above have also been proposed for use on incontinent persons as well as infants to minimize the discomfort caused by the wearing of wet diapers or clothing. This objective, of course, can be achieved by promptly alerting those caring for the incontinent individuals or infants so that a change in the wet clothing can be made as promptly as possible. In addition to the discomfort of wearing wet clothing, rashes, skin irritations, and other adverse physical problems could develop.
Prior art devices for detecting dampness in clothing typically utilize electrodes positioned in the infant's diaper or mattress, with wire connections from the electrodes to an alarm mechanism mounted, for example, on the infant's bed. When urine or excrement provides an electrical connection between the electrodes, an audible or visual alarm is produced. An obvious drawback of this type of arrangement is that the wires connecting the electrodes to the alarm mechanism can interfere with movement of the infant and cause discomfort as well as pose a safety hazard. A number of devices have been proposed which would eliminate the need for wires but such devices typically are bulky, require installation in the fabric of the diaper and have a realtively short range and short life for the wireless transmitting equipment. Exemplary prior art devices are disclosed in U.S. Pat. Nos. 3,460,123, 3,508,235 and 4,205,672.